Last week the check engine light came on. Checked the gas cap first thing and sure enough it was very loose. Says right on the cap that if it isn't tightened, the CEL may come on. Manual says it will reset after several starts. Well, I would say it has been about 10-20 starts and still have the CEL. I'm going to take it in to the dealer to read the codes if it doesn't turn off, but I'm still thinking it is related to the loose gas cap. How many restarts does it take to reset?

Pull the pos side battery cable and leave it off for about a min then reconect it should reset the cel then if it comes on again you know its something other then the gas cap. If it comes on again you can take it to autozone and they will run the codes for you free that way you don't have to pay the stearlership 1/2 hour labor rate or you can go there knowing already what the scanner tells you and see how honest they are with you.

Sometimes it takes a certain number of starts, or a certain cycle of things after the gas cap is tight.....I dont remember, I know it took almost a full week (including a fill up) in our 06 Tundra.

OK, that is a response I was hoping for! Like my original post said, the manual says "several" restarts to reset it. Pretty vague, I just think of less than 10 when I read several. It has been over a week for me, with a tank refill. The truck got 18 mpg on the last tank with the light on for about a third of it. I honestly don't drive the truck all that much, my bicycle is my daily driver. So I probably have less than the average number of starts per timeframe.

To reset that particular sensor, you need to draw a vacuum, then allow it to bleed off a few times. It's not the number of starts as such, it's that the sensor has been able to verify the integrity of the fuel system by seeing it generate and hold a vacuum. That's how the vapor recovery system works.

Just keep the cap tight and drive normally for a while and it will reset.

To reset that particular sensor, you need to draw a vacuum, then allow it to bleed off a few times. It's not the number of starts as such, it's that the sensor has been able to verify the integrity of the fuel system by seeing it generate and hold a vacuum. That's how the vapor recovery system works.

Just keep the cap tight and drive normally for a while and it will reset.

Thanks WATRD. I haven't posted on this forum in ages, but I remember your truck from back when I was glued to this site!

Thanks olharleyman for the advice to hit up Autozone, I had no idea they would read my codes. The code was P0446, and the shop guy said there were 6 of them(?) He did say that seems like a gas cap issue, but if it comes back on blah blah blah..... He let me clear the codes and I am much relieved to have gotten rid of the CEL.